DISEASES OF PLANTS. 349 



but it is believed that the disease will develop within a few years. The obsei'\'a- 

 tions upon these trees are to be continued. 



The perfect stage of Cylindrosporium on Prunus avium, B. B. Higgins 

 (Science, n. ser., 31 {1913), No. 956, pp. 687, 658).— In the fall of 1910 the author 

 began a study of Cylindrosporium as it occurs on species of Prunus in the region 

 of Ithaca, N. Y.. in order to discover the life history and relationship of the 

 organism on the different hosts. Several sweet cherries that had been severely 

 attacked during the previous summer by Cylindrosporium were noted and the 

 fallen leaves examined at different periods during the following winter. In 

 March developing fruit bodies were noticed in abundance on many leaves, and 

 after being brought into the laboratory the fruit bodies showed mature asci. 

 Ascospores taken from the fruit bodies and placed in drops of water on the leaves 

 of P. avium seedlings in the greenhouse gave typical infection, and later similar 

 results were obtained in pure cultures. 



For the perfect stage of the fungus the author proposes the name Coccomyces 

 hiemalis n. sp., a technical description of which is given. 



Causes of deterioration of grapevine in Sicily. — I, On the effects of falls 

 of temperature on grapevines in connection v/ith bramble leaf, L. Petui 

 {Riccrche sulle cause dei deperimeitti delle viti in Sicilia. I. Gontributo alio 

 studio deir azione degli abassamenti di temperatura sulle viti in rapporto air ar- 

 riciamento. Rome, 1912, pp. 110, figs. 97; rev. in Internat. Inst. Apr. [Rome], 

 Mo. Bui. Agr. Intel and Plant Diseases, 4 {1913), No. 1, pp. 137, iS8).— Regard- 

 ing the endocellular fibers observed (B. S. R., 28, p. 245) in all American and 

 European grapevines in Sicily and on the mainland affected with bramble leaf, 

 or roncet, the author states that these formations are identical with those 

 found in the wood of conifers; that these fibers are not found in vines affected 

 with other forms of distortion ; that their formation precedes the external 

 manifestations of roncet; that they are transmitted by cuttings; that this forma- 

 tion is caused by falls of temperature during growth; that the distortion of 

 the shoots produced directly by the late frosts is not the same morphologically 

 or genetically as that due to roncet ; that the sensibility of the tissues due to 

 sudden cold is greater after the first injury; and that these changes are the 

 results of an alteration of a normal process which continues and is transmitted 

 to newly formed cells, independently of a repetition of the cold. It has not 

 hitherto been found possible to prove experimentally that roncet and the endo- 

 cellular fibers are due to the same cause. It is thought that soil structure, 

 shape, etc., found to be favorable to roncet, may be predisposing or comple- 

 mentary factors in its production by cold. 



Black rot of grapes, A. Prunet {Rev. Vit., 39 {1913), No. 1000, pp. 228-232). — 

 This is a brief discussion of the biological characters of black rot in com- 

 parison with those of downy mildew, Oi'dium, and anthracnose. 



It is stated that the primary infection, due to the dispersal of ascospores liv- 

 ing over from attacks of the previous summer, and which do not usually appear 

 after flowering begins, is more important from a standpoint of control than is 

 the secondary infection, from pycnidiospores which appear later. The control 

 of this disease may be secured, it is said, by spraying the vines affected with 

 copper sulphate or sulphuric acid until the blooms appear. 



Botrytis cinerea, G. Lafforgue {Rev. Vit., 39 {1913), No. 1001, pp. 245-254; 

 Prog. Agr. et Vit. {Ed. VEst-Centre), 34 {1913), No. SO, pp. 104-115).— This is a 

 brief discussion of gray rot of grapes, its forms, symptoms, effects, biology, and 

 treatment. 



The loss to the crop of 1912, attributed by some observers largely to downy 

 mildew, is held by the author to have been due mainly to gray rot caused by 



